| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| package org.apache.impala.util; |
| |
| import java.util.List; |
| |
| import org.apache.impala.thrift.TEventSequence; |
| |
| import com.google.common.collect.Lists; |
| |
| /** |
| * Wrapper around TEventSequence so that we can mark events with a single method call. |
| * Events are 'marked' as they happen (so in order, with no time-travel backwards). |
| */ |
| public class EventSequence { |
| private final List<Long> timestamps_ = Lists.newArrayList(); |
| private final List<String> labels_ = Lists.newArrayList(); |
| |
| private final long startTime_; |
| private final String name_; |
| |
| public EventSequence(String name) { |
| name_ = name; |
| startTime_ = System.nanoTime(); |
| } |
| |
| /** |
| * Saves an event at the current time with the given label. |
| * It returns the duration in nano seconds between the last and the current event. |
| */ |
| public long markEvent(String label) { |
| // Timestamps should be in ns resolution |
| long durationNs = System.nanoTime() - startTime_; |
| timestamps_.add(durationNs); |
| labels_.add(label); |
| return durationNs; |
| } |
| |
| // For testing |
| public int getNumEvents() { return labels_.size(); } |
| |
| public TEventSequence toThrift() { |
| TEventSequence ret = new TEventSequence(); |
| ret.timestamps = timestamps_; |
| ret.labels = labels_; |
| ret.name = name_; |
| return ret; |
| } |
| } |